Method of manufacturing prosthetic socket interface

ABSTRACT

A method and system for fitting a compression stabilized prosthetic socket for a patient having an amputated limb and a remaining portion that includes a first socket portion for contacting a patient&#39;s remaining portion of a limb, and a second socket portion for attachment of a prosthetic device. The first socket portion has compression portions having a radius for compressing portions of the patient&#39;s remaining portion of a limb, and relief portions receiving any portions of the patient&#39;s remaining limb which bulge upon the compression applied by the compression portions. The relief portions may be formed as openings or as enlarged radius portions. The fitting method and system can include use of a mechanism to compress bar surfaces against the limb in areas selected to receive compression portions in order to prepare an image for creating the first socket portion.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application is a divisional application of U.S. patent applicationSer. No. 14/156,962 filed on Jan. 16, 2014 which is a continuation of,and claims the benefit of priority from U.S. patent application Ser. No.13/334,952, filed Dec. 22, 2011, now U.S. Pat. No. 8,656,918, which inturn is a continuation-in-part of, and claims the benefit of priorityfrom U.S. patent application Ser. No. 12/945,876, filed Nov. 14, 2010,now U.S. Pat. No. 8,323,353, which in turn is a continuation-in-part of,and claims the benefit of priority from U.S. patent application Ser. No.12/792,728, filed Jun. 2, 2010, now abandoned, which in turn is acontinuation-in-part of, and claims the benefit of priority from U.S.patent application Ser. No. 12/380,861, filed Mar. 4, 2009, nowabandoned, which in turn claims the benefit of U.S. Provisional PatentApplication No. 61/068,263, filed Mar. 4, 2008, all five of suchapplications are incorporated by reference herein

FIELD OF THE INVENTION

The present invention relates to the prosthetic limbs worn by upper orlower limb amputees and in particular, to the portion of a limbprosthesis that is in direct contact with the user's skin.

DEFINITIONS OF TERMS

Socket—is that part of a prosthesis in direct contact with the user'sskin. The word Socket usually implies a traditional socket that isessentially circular in cross section. A traditional prosthesis consistsof an inner socket to interface with the user's skin and an outer socketover it that continues to incorporate the mechanisms that comprise thenext distal structure which may be a joint or a device to function as afoot or gripping device. The inner and outer sockets may be separatestructures or may be unitary consisting of a single unit.

Interface—is often used as a synonym for socket, but is more oftenreserved for socket-like structures that have openings in the outersocket and occasionally in both the outer and inner sockets.

Cast—is a thin layer of wet plaster impregnated gauze wrapped around aresidual limb and the surrounding body parts and then permitted toharden to reproduce the shape of the limb. While the plaster ishardening, pressure from the hands of the plaster technician oftenmodifies the shape to accommodate the underlying boney anatomy.

Positive Model—is the plaster model that results from filling a castwith plaster or similar material. Modifications by adding andsubtracting plaster are made to this model before its outer surface isused to define the shape of the user's socket or interface.

Check Socket—is a temporary socket made over the model and used to testwhether the modifications have had the desired effect on the fit of theresulting socket.

Channel—is used here to describe a longitudinal area where the wall of asocket is depressed inward as close to the underlying skeletalstructures as is comfortable.

Relief Area—is the region in a socket system between two channels oraround or near a compressed area which provides a place for thedisplaced tissue to migrate.

Lost Motion—is the motion of the skeletal structures with respect to theprosthetic interface when force is applied between the two as wouldoccur as an amputee tries to move the prosthesis as a whole. In atraditional socket, lost motion occurs when the bone moves toward thesocket wall a substantial distance before imparting force to the wall.

Compression Bar—is a long flat bar typically a little shorter than theshaft of the remaining long bone(s). The width of the bar is usuallyabout ten percent of the circumference of the remaining limb.

Optimal Tissue Compression—is compression of the tissue against thesocket wall such that lost motion is minimized without causingdiscomfort to the user.

High-fidelity Interface or device—is the name given to the socket orinterface that utilizes compression stabilization as the basis for itsfunction and physical structure.

BACKGROUND OF THE INVENTION

Historically the prosthetic user interface has been a cylindrical socketthat merely surrounds the remaining limb part with some contouring ofthe proximal brim so that it will accommodate the shape of the nextproximal joint or body part. Typically, this socket is made by taking aplaster cast over the limb and filling it with plaster to form apositive model of the limb. Minor changes are made to this shape torelieve boney prominences. When this model is used to create a socket bylaminating or thermoforming a layer of plastic there over, the resultingsocket mainly encapsulates the limb part. Conventionally, nomodification of the traditional model is done. This opportunity tospecifically enhance the resulting structure's ability to impart desiredmotion to the complete prosthesis, and to prevent undesired motion fromoccurring, has been overlooked, even though these are the most importantfunctions of the interface. The traditional encapsulating or closedvolume socket merely contains the soft tissue but does little or nothingto prevent lost motion between the socket and the underlying skeletalstructure.

Some improvements have been made in the traditional interface. Inparticular, many technicians replace the fully encapsulating outersocket with a frame having one or more openings. This change isaccompanied by making the inner socket of a flexible material. Theresulting frame-style design usually is more comfortable. New materialssuch as carbon fiber composites add rigidity where needed especially inopen frame designs. New flexible materials allow the socket wall to flexin other areas for comfort. Even when these newer flexible materials areused, the soft liner still fully encapsulates the remaining limb astraditionally done, and thus provides a compressive or elastic force toall of the limb's soft tissue.

Conventional laminations over a plaster model work best when thesurfaces of the model are convex facing outward, following the generalcontours of the outside surface of the limb.

SUMMARY OF THE INVENTION

In a preferred embodiment of the invention, a mold (negative model) ismade by making a cast of a remaining limb on which a prosthesis will beused. From the mold/cast, a positive model is made of the remaininglimb. There are deep channels formed in the positive model, which are acause of excessive thickness in these areas when conventional laminationprocedures are used. Where the areas between the channels are to be leftopen, however, the model may be brought almost flush with the edges ofthe compressed areas. This alteration permits a much strongerlamination. Another technique to strengthen the resulting struts is tocorrugate the compression channel area to create a resistance to flexupon lamination.

When taking a cast of the area above the knee, prosthetists are oftenassisted by using jigs especially to establish the shape of the brimarea for transfemoral sockets. In the new socket technology of thisinvention, one may also use a jig to assist in achieving an optimal castof the area above the knee.

PREVENTING LOST MOTION

In one embodiment, a basis of this invention stems from a simpleobservation using a procedure such as described below. A person holdshis/her arm in a fixed position so that an experimenter cannot easilymove the arm side to side. The experimenter then pushes with a finger onthe fleshy area over the long bone of the upper arm. Typically, thefinger will push into the soft tissue a centimeter or more before itcompresses the tissue against the bone and no further motion is possiblewithout the subject moving. During compression, tissue moves aside awayfrom the area of compression. From the inventor's knowledge, no priordesigns have specifically allowed for the displacement of tissue as arequirement for achieving stability even if local compressed areasexist. For a long bone to be fully stabilized with respect to theprosthetic interface, compression must be applied in a specific way.Typically, three or four channels are created in the socket along theentire length of the bone except at the very ends. Accordingly, thechannels extend proximate to ends of the bone, e.g. at least eighty andmore preferably at least ninety percent of the existing longest bone inthe existing limb. The inner surfaces of these channels compress thetissue against the long bone until little further motion is possible.For this compression to be effective, there must be a longitudinalrelief area between each pair of channels. The channels and the reliefareas are two key elements of a preferred embodiment of the inventionand both must be present for optimal performance. In a more preferredembodiment, a third key element is that at least three channels areneeded to impart full stability.

CREATING THE COMPRESSION STABILIZED SOCKET INTERFACE

The traditional prosthetic socket is created by taking a cast, making apositive model, and modifying the model to create a form for shaping afinal socket interface. An important element of a preferred embodimentof this invention is the use of the traditional sequence in a new way.Three to four compression bars are made prior to taking the cast. Theseare tested by spacing them appropriately around the remaining limb andpushing in. Care is given to both the physical and anatomical structuresof the limb in determining proper placement. In the case of the upperlimb, specifically the humeral level in which positional precision andlifting capacity take precedent, the locations of these compression barsare biased toward stabilization in flexion and abduction, the two mostcommon functional motions utilized, resulting in narrower relief windowsin the anterior and lateral areas of the socket. The length, width, andcurvature of the bars are adjusted until they lock the underlying bonein place when equal pressure is applied to the bars. The individual barsare checked to see if they rock end-to-end when pressure is shifted inwhich case a change in shape is indicated. Before taking the cast, theprosthetist must decide how to arrange the bars around the limb so thatforces are optimally transmitted when the resulting interface is used.The underlying location of nerves and other structures will determinethe exact angular orientation of the bars and may determine the optimumnumber of bars to use.

The cast is taken by applying a loose wrap of wet elastic castingplaster. The bars are then placed in the pre-planned positions, pressedinto the elastic wrap and soft tissue by hand or with a casting jig withsufficient force to impart substantial compression on the limb and heldin place while the plaster sets. It is important for the wrap to be ableto stretch so that the displaced tissue has somewhere to go. Even in thebest of circumstances, the plaster will prevent the bars from achievingoptimal penetration. This is corrected during the cast rectificationstage. Before, during or after the channels in the plaster and thebulges in between are sufficiently set, the proximal parts of the castare taken in the usual manner. However, some areas in this secondaryarea of the wrap may also need to be compressed by the fingers of thecast taker to create additional areas of pre-compression.

For taking a femoral level cast, the distances and forces needed aregreater and a bar-location jig is of great help. This jig is an integralpart of the invention for femoral casting and femoral interface socketsand could also be used if desired for humeral casting. The jig consistsof two or more stiff “d”- or “c”-shaped rings with the flattened surfaceof the d-rings or the open surface of the c-rings positioned to themedial or inside area next to the midline of the body or the oppositeleg if present. These rings are large enough to allow some space insidethe rings when they are placed around the limb. Each ring can accept asingle screw attachment or plurality of screw attachments. Eachattachment can be oriented azimuthally around the ring and then lockedin place. Each attachment has a screw or screws aimed at the center ofthe ring capable of applying force to one of the channel-forming bars.In addition, the attachments are open on one of the sides that faceparallel to the limb in the d-ring design. This opening permits theprosthetist to remove a single pair of attachments and the underlyingbar after the preliminary setup described below. The c-ring designinherently already has this opening. Small snap-in pockets along theoutside of each bar and the fact that the screw ends are sphericalprevent slipping once the bars are in place. In the ideal embodiment,the pockets have a restriction at the opening that makes the attachmentof the screw ends act like pop beads to hold the screw end to the bar.In a typical cast taking at the femoral level, two rings are used andeach has four attachments oriented approximately ninety degrees apart.In the design utilizing two screws for each compression bar, theattachment screws are placed in pockets on the bars about twenty percentof the length of the bar in from the end. Before the cast is taken, theprosthetist experiments and selects the best length and width for eachbar and the optimal location. To speed application during the actualcast taking, all positions are marked with the anticipated extracircumference of the added plaster wrap accounted for.

An alternative jig in accordance with the invention has a support memberto support and position channel-forming bars, or paddles, so that thepaddle surfaces can be maneuvered to press inwardly against targetcompression areas for a selectable distance and permit displacement oftissue to uncompressed areas. In a particular embodiment, the paddlesare removable, so the user can choose the number, shape, and size ofpaddles desired. Four paddles may be advantages in particularapplications.

The operation of maneuvering, for example, can be accomplished with aprojection member connected to and actuated by an attachment mechanism,which is attachable to the support member. The attachment mechanism canadvantageously be movable along the support member and locked into adesired location. A particular attachment mechanism can be operable topress the projection member inwardly against the body part and to lockthe projection member in place when it has reached the distance requiredfor the desired compression.

The support member, for example, can be attachable at particularlocations to a stand, which is suitable to support a patient. Thesupport member can then be moved up or down along the stand to adjustthe jig to the size of the patient and the desired imaging area. Tofurther support the patient, a particular example includes a handle onthe upper end of the stand. In an advantageous example, the supportmember can pivot on the stand, so a user can further maneuver thesupport member and the attached paddles into a desired position forimaging. The support member can be removed from the stand, for example,to allow different sized support members to be attached and used withthe stand.

After the cast has been filled to create a positive model, the plastertechnician will usually need to deepen the channels before pulling athermoformed check socket out of transparent plastic. If a solid-bodiedcheck socket will be utilized, then additional plaster must be addedover the relief areas of the positive model to allow sufficientdisplacement of soft tissue into the check socket's relief areas.Usually several check sockets will be needed. As each is applied to theuser, the fit and stability of the check socket is evaluated. The colorof the tissue will tell the experienced practitioner where too muchcompression is being applied and where there is too little. In addition,substantial forces should be applied in all directions to ensure thatthe stabilization is optimal. Since the compression stabilized interfacedesign requires that the areas between channels be left free orsufficiently relieved for tissue movement, there is good reason forleaving these areas fully open in the check socket unless anencapsulating or solid-body interface is desired. The user can then morereadily perspire and dissipate excess body heat. With three or more longopenings in the socket wall, a traditional cloth laminate is usuallyreplaced by a stiff, strong carbon fiber reinforced laminate in the formof a frame.

Usually a temporary assembly of the distal prosthetic components isadded to the final check socket and tested before the shape of the checksocket is approved for creating the definitive prosthesis. For approval,the interface must transmit force and motion to the prosthesis in everydirection that the user will require with minimal lost motion betweenthe interface and the rest of the prosthesis.

In a presently preferred embodiment of the invention, there is a limbinterface device. The limb interface device has either an encapsulatingdesign with adequate soft tissue reliefs or an open cage or strut-typeconfiguration of rigid, semi-rigid, or dynamically adjustable strutsappropriately contoured to a patient's residual limb. The open cage orstrut-type configuration contains windows through which soft tissue canflow out of the interface confines.

The limb interface device may have any of various prosthetic componentsattached to it to provide an upper or lower extremity prosthesisextending from the distal end of the interface device. The regions ofcompression in both the encapsulating and strut-type embodiments areconfigured and aligned in such a way as to transfer skeletal movement asefficiently as possible such that interface response to volitionalmovement and interface stability are maximized. Optionally, stabilizersor other devices may be attached to a proximal end of the limb interfacedevice.

In the open cage or strut-type configuration, the strut edges can beconfigured such that they are either flexible enough or shapedappropriately to mitigate edge pressure and hence soft tissue stress, ora material can be fitted to the struts such that it extends just beyondthe border of the rigid or semi-rigid edge and provides a more gradualtransition of pressure at this location.

In another preferred embodiment, the interface device may have theability to alter the stiffness of the strut assembly itself on demand orautomatically in response to applied loads such that edge pressure oroverall strut compression is varied appropriately to prevent skin orunderlying soft tissue damage. Finally, an inner, highly flexiblemembrane may be utilized that encapsulates the entirety of the limb andis placed between the strut assembly and the limb yet still allowssufficient soft tissue flow beyond the confines of the strut assemblysuch that edge pressure on the soft tissue and redundant intrinsicskeletal motion are minimized.

Although embodiments of the present interface assembly finds particularapplication with prosthetic limbs, it is also to be appreciated that theinterface assembly may be used in other applications such as orthoticsor other interface applications involving the human body.

Still other objects, advantages and constructions of the presentinvention, among various considered improvements and modifications, willbecome apparent from the detailed description provided hereinafter. Itshould be understood that the detailed description and specificexamples, while indicating a presently preferred embodiment of theinvention, are intended for purposes of illustration only and are notintended to limit the scope of the invention.

In some parts of the orthotic and prosthetic industry, cast taking hasbeen replaced by laser scanning of the residual limb and the creation ofa virtual solid model. It is anticipated that simple algorithms can becreated to permit insertion of channels and bulges in a virtual modelsuch that the area inside the virtual wall of any cross section of theresidual limb would remain the same. Such an algorithm automaticallycreates appropriate bulges when the technician moves a portion of thewall toward the skeletal structures in the virtual model. Principles ofthe embodiments of the invention are not changed when the model forcreating the definitive interface structure is based on a plaster castor on a virtual model produced with software.

In a preferred embodiment, there is a prosthetic socket which preventslost motion between an amputee's remaining limb and the prosthesis byselectively compressing tissue against the bone in some areas whileproviding relief in other areas so that displaced tissue is accommodatedwhen forces are applied between the bone and the interface. Additionalembodiments of the invention include methods for creating the new socketdesign.

It is an object of various embodiments of the present invention toprovide a prosthetic interface within which the individual's upper orlower extremity residual limb part is captured with greater stabilitythan in known prior art.

It is a further object of various embodiments of the invention toprovide a mechanism to selectively compress the soft tissue between theresidual limb's skeletal structure and socket structures to minimizelost motion when the skeletal structures of the residual limb move withrespect to the socket and attached prosthesis.

It is a further object of various embodiments of the present inventionto provide a plurality of areas of compression parallel to the long axisof the major bone or bones of the residual anatomy.

It is a further object of various embodiments of the present inventionto provide open or low-compression relief areas between said areas ofcompression so that said compression is not impeded by the inability ofthe underlying tissue to flow or migrate sideways.

It is a further object of various embodiments of the present inventionto provide a method for taking a cast of the residual limb that resultsin an approximation of the desired final shape of the socket interface.

It is a further object of various embodiments of the present inventionto create areas of compression in a plaster cast parallel to the longaxis of the residual limb during the process of cast taking with bulgesin between that will define areas of relief in the complete prostheticinterface.

It is a further object of various embodiments of the present inventionto provide check sockets where areas of relief are created by leavingthe socket wall completely open or are large enough in the encapsulatingversion to allow for sufficient soft tissue displacement.

It is a further object of various embodiments of the present inventionto provide definitive prosthetic interfaces where areas of compression,both with respect to the underlying bone as well as with respect to thearea of compression just proximal to the bulging soft tissue, tostabilize the longitudinal motion of the prosthesis with respect to theskeletal anatomy thus aiding in suspension and weight bearing.

It is a further object of various embodiments of the present inventionto provide definitive prosthetic sockets where a soft liner covers thelimb but is stabilized by a frame there over with the frame performingthe functions of a traditional outer socket. (If such a liner is used,the model over which it is formed must have bulges between thecompression channels large enough to create a liner with little or notissue compression in the areas between the areas of compression.)

It is a further object of various embodiments of the invention toprovide areas into or through which a significant amount of soft tissueof the said limb can flow freely, without restriction or with minimalrestriction so as to permit sufficient soft tissue flow away from areasof compression along the shaft of the bone or bones in theaforementioned areas of high compression.

It is a further object of various embodiments of the present inventionto take advantage of the anatomical response such that tissue can becompressed against bone just so far before further motion is impeded ifthere is room for the displaced tissue to move out of the way.

It is a further object of various embodiments of the present inventionto create prosthetic sockets with longitudinal grooves alternated withareas sufficiently open that the displaced tissue suffers nocompression.

It is a further object of various embodiments of the present inventionto create sockets that have three or more compression channels so thatlost motion is prevented in all directions.

It is a further object of various embodiments of the present inventionto shape the interior surfaces of the grooves such that when theprosthesis is loaded the local pressure along the length of the bone isequal without excessive pressure at the ends.

It is a further object of various embodiments of the present inventionto provide means for creating a prosthetic interface by applying aplurality of bars or a loose plaster wrap during the cast takingprocedure.

It is a further object of various embodiments of the present inventionto provide a jig for holding the bars in position during cast taking.

It is a further object of various embodiments of the present inventionto provide a jig having two or more rings larger in diameter than thelimb. Each ring has a single or plurality of snap-in-place screwholder(s) with adjustment screws oriented so the axis of the screwpasses through the center of the ring.

It is a further object of various embodiments of the present inventionto provide screw holders that are applied to the ring by moving parallelto the axis of the ring. This feature permits a bar screw holder or abar and two screw holders to be removed from a pair of rings as a unit.

It is a further object of various embodiments of the present inventionto provide adjustment screws with spherical ends.

It is a further object of various embodiments of the present inventionto provide a snap-in socket or plurality of snap-in sockets along thecenter line of the outside of each bar which accept the spheres on theadjustment screws.

It is a further object of various embodiments of the present inventionto provide bars with center sections that telescope so bar length can beadjusted as well as to offer different length bars to be snapped inplace depending on the application.

It is a further object of various embodiments of the present inventionto provide a jig having a support member attached to a stand where thesupport member is maneuverable to press paddles against targetcompression areas selectable distances and permit displacement of tissueto uncompressed areas.

It is a further object of various embodiment of the present invention toprovide a jig with a stand that can support a patient and where thestand can be adjustable to accommodate patients of different sizes.

It is a further object of the various embodiment of the presentinvention to provide a jig with different sized support members fordifferent sized patients.

It is a further object of various embodiments of the present inventionto provide a jig having projection members for pressing paddles, wherethe projection members can be moved along a support member to positionthe projection members to press against particular target compressionareas.

It is a further object of various embodiments of the present inventionto provide a jig that locks paddle surfaces in place once the paddlesurfaces are maneuvered to press on target compression areas aselectable inward distance.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view from an anterior position of a transhumeralhigh-fidelity interface device in accordance with a first preferredembodiment of the invention, where the device has an open cage orstrut-type structure;

FIG. 2 is a perspective view from an anterior position of a transhumeralhigh-fidelity interface device in accordance with a second preferredembodiment of the invention, where the device has a closed structure;

FIG. 3 is a cutaway view from the top of the interface device of FIG. 2,showing an interior thereof;

FIG. 4 is a view of the device of FIG. 1 on a patient's left arm;

FIG. 5 is a perspective view from a medial position of a transradialhigh-fidelity radial interface device as a closed structure;

FIG. 6 is a perspective view from an anterior position of a transfemoralhigh-fidelity interface device in accordance with a fourth embodiment,where the device has a closed structure;

FIGS. 7a and 7b show an example of a jig design utilized fortransfemoral cast taking in preparation for the creation of atransfemoral high-fidelity interface;

FIGS. 8a and 8b show the anterior and posterior perspectives of anexemplary transfemoral high-fidelity interface attached to prostheticcomponents;

FIG. 9 is a drawing showing a casting

FIG. 10 is a drawing showing a mold formed from the casting;

FIG. 11 is a flow chart showing steps in a process of an embodiment ofthe invention for making a high-fidelity interface for a prosthesis andlimb, preferably a lower limb; and

FIG. 12 is a flow chart showing steps in an alternate process of anotherembodiment of the invention for making a high-fidelity interface for aprosthesis and limb, preferably an upper limb.

FIG. 13 is a drawing showing a jig with a single support member andstand.

FIG. 14 is a flow chart showing steps in a process of an embodiment ofthe invention for imaging.

FIG. 15A-C is a drawing showing compression bars pressing against two,three, or four target areas on a limb to a maximum compression point inorder to capture the motion of the underlying bone, while allowingdisplacement of tissue into noncompressed areas.

FIG. 16 is a drawing illustrating motion capture of the underlying boneby compression bars in comparison to the broader motion that isexperienced without compression bars.

FIG. 17 is a drawing showing the hands of a technician locatingcompressions bars over target areas where compression is desired, whileallowing displacement of tissue into noncompressed areas.

FIG. 18 is a drawing showing a technician pressing compression bars ontarget areas after casting material has been applied to a limb.

FIG. 19 is a drawing showing compression bars pressed in place usingelastic wrapping material.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

As shown in FIG. 1, a the transhumeral open-cage interface embodiment,there is an upper portion 1, which has both an anterior stabilizer 2 anda posterior stabilizer 3 and which extends in a proximal (in this casetoward a patient's shoulder) and medial (toward a patient's midline)direction from a lower portion 4 to stabilize the interface on apatient's body. Although stabilizers 2 and 3 are not required, they arerecommended to impart or enhance rotational stability. The lower portion4 (below line 5) has an open-cage structure. Dashed horizontal line 5demarcates the upper and lower portions. The lower portion 4 of thisopen-cage embodiment has multiple, e.g. three or four struts 6, whichlook like fingers that extend along the long axis of the residual limband are designed to partially encompass the residual limb, allowing softtissue to flow through windows 7.

As shown in FIG. 2, a transhumeral solid-body interface embodiment,there is an upper portion 1 a, which has both an anterior stabilizer 2 aand a posterior stabilizer 3 a and which extends in a proximal (in thiscase toward the shoulder) and medial (toward the midline) direction fromlower portion 8 to stabilize the interface on the body. Althoughstabilizers 2 a and 3 a are not required, they are recommended to impartor enhance rotational stability. In this embodiment, lower portion 8 isa solid body structure. A dashed horizontal line 5 a demarcates theupper and lower portions. The lower portion of this solid-bodyembodiment has multiple, e.g. three or four, compression areas 9 andsoft tissue relief areas 10 that extend along the long axis of theresidual limb and are arranged circumferentially in an alternatingcompression-relief pattern as shown. Soft tissue relief areas 10 musthave a volume sufficient to cleave displaced skin and other tissue fromcompression applied by compression areas 9.

In FIG. 3, an interior of the transhumeral solid-body interfaceembodiment is shown, with alternating compression areas 9 and reliefareas 10 indicated.

In FIG. 4, a patient is shown wearing a transhumeral open-cage interfaceembodiment such as that of FIG. 1 with a suspension liner 30 of minimalthickness or of sufficient stretch to minimally restrict soft tissueflow through the relief windows. Struts 6 providing soft tissuecompression and windows 7 allowing soft tissue flow are indicated.

In FIG. 5, a transradial solid-body interface is shown. In thisembodiment, there is an upper portion 11, which comprises the area ofthe interface proximal to olecranon 12 and cubital fold 13. A lowerportion 14 has multiple, e.g. three or four, compression areas 15 andsoft tissue relief areas 16 that extend along the long axis of theresidual limb and are arranged circumferentially in an alternatingcompression-relief pattern as shown.

In FIG. 6, a transfemoral solid-body interface is shown. This embodimenthas multiple, e.g., three or four, compression areas 17 and soft tissuerelief areas 18 that extend along the long axis of the residual limb andare arranged circumferentially in an alternating compression-reliefpattern as shown.

In FIGS. 7a and 7b , there is shown a tool for use in imaging (andparticularly helpful for the lower limb), which tool optionally may beused with various embodiments of the invention. Imaging is a process torender a model of the limb using plaster bandage, laser scanning orother such technique. Imaging of a limb under compression may be done tocreate the model. This tool is essentially a connected set of adjustablebars attached to screws which in turn are connected to a circumferentialor partially circumferential ring that allows this tool to be placedover the limb either before, during or after the imaging process andthat applies the appropriate compression to the soft tissues of the limbin desired target areas while allowing redundant soft tissue to flowthrough the areas between the struts unhindered.

More specifically, the jig consists of a multiplicity of paddles 101 forpushing inward against the limb remnant of an amputee. For mostpurposes, four paddles preferably are used. For the configuration shown,eight sectors 110 are assembled into two rings. Eight screws are used atlocations 111 to assemble the rings.

In FIG. 7b , a screw (not shown) is inserted into clearance hole 112 tosecure the turnbuckle holder 108 (also shown in FIG. 7a ) to the sector110. Until the screw is tight, the holder is free to rotate with respectto the sector. The turnbuckle rod 106 is threaded with an eyelet 113 onthe far end to connect to paddle holder 105. A pin attaching these twoparts is inserted into hole 114. Paddles 101 each have a channel 103into which a slider 102 is captured. This slider has two threaded bosses104 which are secured to paddle holder 105 by nuts (not shown). Byloosening these two nuts, the slider may be repositioned along thepaddle.

To adjust the position of the paddle, a threaded wheel 107, shown inFIGS. 7a and 7b , is turned. In the configuration shown in FIG. 7a ,there are a total of eight turnbuckle assemblies to position the paddlesin contact with the amputee's limb. Preferably, the paddles are madefrom a rigid, inexpensive plastic that can be trimmed to a width andlength suitable to the individual amputee fitting. All of the othercomponents are preferably reusable.

As shown in FIG. 8a (an anterior perspective) and 8 b (a posteriorperspective), an exemplary prosthetic component set 21 is attached toone device 22. Various prosthetic components may be attached to thedevice by any one of various methods currently available or available inthe future. The device may have at a proximal end any one of varioussupport structures known in the art or developed in the future.

In a method in accordance with an embodiment of the invention, aninterface device with open-cage or strut-type is fitted onto a person.

First, it is determined whether a patient needs a transradial (radiallevel) device, a transhumeral (humeral level) device, a transtibial(tibial level) device, or a transfemoral (femoral level) device. Thepatient or prosthetist may select a closed device or an open cagestrut-type high-fidelity device.

Second, the patient's limb radius is determined at one or morelocations. Third, the device is essentially crimped during modificationor creation of the device until sufficient compression from the at restradius of the patient's limb at the cage or strut region of the deviceis at a desired amount. The desired amount of compression will depend inpart on the patient's bone size, body fat, and other tissue parametersat the area of the cage or strut. The compression generally is at least20% or at least 30% from the at rest radius of the limb. Typically,compression will be from 20% to 70% or 30% to 70%. As described belowfor an alternative embodiment and illustrated in FIG. 15A-C, the amountof compression is sufficient such that there is minimum redundant tissuebetween the maximum point of compression 303 and the target bone 305contained within the interface such that motion capture of the bone ismaximized while retaining sufficient comfort to allow the wearer towithstand the compression for a useable amount of time and to ensureadequate blood flow over time, which can be ascertained through the useof a blood perfusion sensor and monitor. The blood perfusion sensor canbe utilized during casting, diagnostic interface assessment or in thedefinitive socket.

A usable amount of time for an interface is the amount of time theoperator expects the person being fitted with the interface would wearthe interface on a typical day. It is to be appreciated that this amountof time is different and unrelated to the amount of time necessary toperform the imaging process described for the various embodiments of thepresent invention.

However, compression can be lower than 20% or higher than 70% dependingupon bone size, body fat and other tissue parameters, and theprosthetist and/or physician will use the blood perfusion sensor andmonitor and make a determination of the safety and effectiveness of theparticular amount of compression for the particular patient.

Fourth, the modified or rectified high-fidelity device with an innerradius or inner radii of size that can be fit over the distal (free) endof the patient's limb (for fitting with a prosthesis) is selected, andapplied to the patient's limb, e.g., by sliding onto the limb.

Creation and Fabrication of High-Fidelity Interface

In a method in accordance with an embodiment of the invention, aninterface device with open-cage (strut-type) or solid-body configurationis fitted onto a person.

First, it is determined whether a patient needs a wrist disarticulationdevice, a transradial device, a transhumeral device, a symes device, atranstibial device, a knee disarticulation device, a transfemoral deviceor a hip disarticulation device. The patient or prosthetist may select aclosed or open cage strut-type high-fidelity device as disclosed herein.

Second, the patient's limb radius is determined at one or more locationsalong the limb where the interface device will be fit.

Third, the interface is created using one of several different methods,all of which require modification by the prosthetist to complete fittingof such a final socket.

In FIG. 18. one method commonly employed is to cast the patient's limbutilizing a plaster bandage 301. This casting allows the prosthetist orclinician to add compression forces to the plaster wrap and hence to thelimb in the target areas that will hold this compression and allow forsubsequent tissue relief between these compression areas as the plastersets.

FIG. 15A-C depicts compression bars 302 pressing against a target areaof a limb and displacing tissue into relief areas 308. The amount ofcompression is sufficient such that there is minimum redundant tissuebetween the maximum point of compression 303 and the target bone 305contained within the limb such that motion capture of the bone ismaximized while retaining sufficient comfort to allow the wearer towithstand the compression for a useable amount of time and to ensureadequate blood flow over time.

FIG. 16 illustrates motion capture where compression bars 302 lie alongthe length of the bone 305 and press inwardly from the at rest radius ofthe limb 306. Absent compression bars, the bone and the maximum point ofcompression 303 would move outwardly to a socket wall (not shown) to anarea on the limb 307 approximately at the at rest radius. Thisrepresents the lost motion of the skeletal structure with respect to aprosthetic interface when force is applied between the two as wouldoccur as an amputee tries to move the prosthesis as a whole. In atraditional socket, this lost motion occurs when the bone moves towardthe socket wall a substantial distance before imparting force to thesocket wall. By pressing the compression bars inwardly during casting tothe maximum point of compression, lost motion within the resultantinterface is minimized without causing discomfort to the user.

In FIG. 18, the cast 301, which will function as a negative model ormold, is removed and filled with liquid plaster.

The liquid plaster is allowed to set in the mold.

Once the liquid plaster has solidified, the plaster bandage 301 (mold),depicted in FIG. 18, surrounding the solid (positive) model is removed.The positive model is now revealed to which the prosthetist or clinicianapplies additional compression to the target areas by carving directlyon the model. Carving on the positive model creates a pressure orcompression point on the target areas because the “negative” model (thesocket being molded from the positive model) will now have a largerinwardly facing compression area.

Another way to generate the limb shape to be modified is to use ascanner to obtain the image shape and then modify the digital imageaccordingly using well known software, e.g., on a computer such as alaptop. This digital model (as modified to apply targeted compressionand relief) can then be sent to a carver or 3d printer to generate aphysical positive model over which a negative model (mold) can becreated for fitting or additional fabrication.

In order to determine appropriate compression levels, the device isessentially crimped during modification or creation of the device untilsufficient compression from the at rest radius of the patient's limb atthe cage or strut region of the device is at a desired amount. Thedesired amount of compression will depend in part on the patient's bonesize, body fat, and other tissue parameters at the area of the cage orstrut. The compression generally is at least 20% from the at rest radiusof the limb. Typically, compression will be from 20% to 70%, or at least30% to 70%. For certain patients, such as very muscular, or those havingcalcification, the minimum compression to achieve the advantages of theinventive method may be a little below the above minimum ranges, and forcertain patients, such as obese patients or others with extremely fleshyskin, higher than 70% compressions may be appropriate. However, comfortand medical safety can dictate the final appropriate amount ofcompression for any particular patient.

The amount of compression is sufficient such that there is minimumredundant tissue between the maximum point of compression and the targetbone contained within the interface such that motion capture of the boneis maximized while retaining sufficient comfort to allow the wearer towithstand the compression for a useable amount of time.

Fourth, the decision is made whether a diagnostic interface (transparentthermoplastic socket for analysis of fit and function prior to creatingthe definitive model) or a definitive interface, typically consisting ofa laminated framework, is to be created.

Over the now modified or crimped model, in order to create thediagnostic interface, a thermoplastic material is heated and draped orblister-formed, preferably under vacuum, to render a new negative model.Once the thermoplastic has cooled and become rigid, the plaster is thenremoved from within the thermoplastic interface and the interface istrimmed and smoothed and is of sufficient stiffness and transparency toallow the clinician to don it on the patient and judge the fit andpressures acting on the limb. This model can be removed from thepatient's limb and trimmed or heated to change its boundaries orperimeter and shape, including the amount of compression or relief thatis applied to the limb based on what is observed and comments from thewearer.

In order to create the definitive interface, an acrylic laminate (withor without stiffeners such as carbon fiber, Kevlar®, i.e., para-aramidsynthetic fiber, etc.) or similar can be vacuum formed directly over themodel or in the case of a frame style interface with a flexible linerand rigid frame, over an inner flexible liner that has been previouslyvacuum-formed over the same model.

The now compressed negative socket, whether in diagnostic or definitiveform can be donned by either a push-in or pull-in method, with thelatter being preferred due to the high levels of compression applied tothe limb. This compression imparts friction on the skin during donningand hence makes it more difficult to get all the limb tissue down in theinterface unless a donning sock or similar is used to pull the tissuein. The pull-in method utilizes a donning sock or similar such devicethat surrounds the limb and is pulled through a distal aperture at thedistal end or bottom of the interface. As the wearer pulls down on theend of the donning sock and pulls it through the aperture, the limb ispulled down into the interface until fully seated.

In FIG. 9, an example of a casting 240, e.g., for an upper limb, isshown.

In FIG. 10, a socket 202 having compression regions 209 and reliefregions 210 is shown on a patient's limb, e.g., an upper limb.

FIG. 11 is a flow chart showing steps in a process of an embodiment ofthe invention for making a high-fidelity interface for a prosthesis andlimb, preferably a lower limb, the lower limbs being the ones that willbe bearing weight of the wearer's body; and

FIG. 12 is a flow chart showing steps in an alternate process of anotherembodiment of the invention for making a high-fidelity interface for aprosthesis and limb, preferably an upper limb.

In FIG. 11, in step 221, and as depicted in FIG. 17 (for an upper limb),a technician will locate biomechanically, anatomically andphysiologically appropriate location of compression bars to be appliedto a lower limb during casting or scanning such that there arealternating compression areas (under the compression bars 302) andrelief areas 308 arranged longitudinally along shaft of long bone.

In step 222, a technician will, if casting, preferably use a casting jigas shown in FIG. 7a, 7b , or FIG. 13, both before and after the plasterbandage 301 (depicted in FIG. 18) is applied to the limb, in order toidentify the locations described above and to apply appropriatecompression to the limb underweight bearing conditions after the plasterwrap is applied respectively. If scanning, the technician will identifylocations for compression bars such that they are retained in themodification software after scan is complete.

In step 223, a technician will create positive model from negative modelcreated above and modify such that the longitudinal compression areascorrespond to at least a 20% (or 30%) (up to 70%) diameter reduction ascompared to the uncompressed measurement if anatomically and physicallyappropriate. In some cases, compression below 20% or above 70% may beacceptable.

In step 224, a technician will create a diagnostic, negative model fromthe positive model above including longitudinally extending compressionregions corresponding to the amount of compression determined above, andrelief regions adjacent and in between the compression regions forreceiving at least a volume of the patient's fleshy portions on theremaining limb that are to be displaced by the compression regions. Therelief/release regions can be enclosed or completely open provided thereis minimal restriction to soft tissue flow.

In step 225, which is optional, one preferably will put on al sock orsleeve to facilitate donning by pulling the limb down into the socketmore completely.

In the process of FIG. 12, in step 231, and as depicted in FIG. 17, atechnician will locate biomechanically, anatomically and physiologicallyappropriate location of compression bars to be applied to (upper) limbduring casting or scanning such that there are alternating compressionareas (under the compression bars 302) and relief areas 308 arrangedlongitudinally along shaft of long bone.

In step 232 and as depicted in FIG. 18, the technician will, if casting,apply a plaster bandage 301 to limb and over this apply compression bars302 in the predetermined locations above. If scanning, the technicianwill identify locations for compression bars such that they are retainedin the modification software after scan is complete.

In step 233, the technician will, create positive model from negativemodel created above and modify such that the longitudinal compressionareas correspond to at least a 20% (or 30%) (up to 70%) diameterreduction as compared to the uncompressed measurement if anatomicallyand physically appropriate. In some cases, compression below 20% orabove 70% may be acceptable.

In step 234, the technician will create a diagnostic, negative modelfrom the positive model above including longitudinally extendingcompression regions corresponding to the amount of compressiondetermined above, and relief regions adjacent and in between thecompression regions for receiving at least a volume of the patient'sfleshy portions on the remaining limb that are to be displaced by thecompression regions. The relief/release regions can be enclosed orcompletely open provided there is minimal restriction to soft tissueflow.

In step 235, which is optional, one preferably will put on al sock orsleeve to facilitate donning by pulling the limb down into the socketmore completely.

In FIG. 13, there is shown another embodiment of a tool for use inimaging. This embodiment includes a support member 241 for positioningpaddle surfaces 242 against target areas. In the embodiment depicted,four paddles 243 are used. The paddles can pivot on a detachable,lockable paddle joint 244, such as a lockable ball joint, between thepaddle and a projection member 245 to allow each paddle to pivot to thedesired angle relative to the target area and to allow different sizedand shaped paddles to be installed on the projection member.

The projection member 245 is connected to and actuated by an attachmentmechanism 246 and the attachment mechanism is attachable to the supportmember 241. A slider 102, channel 103, threaded bosses 104, and paddleholder 105, as depicted in FIG. 7b , can also be included in theembodiment shown in FIG. 13 for added maneuverability of the paddlesurfaces 242, in which case the projection member would attach to thepaddle holder, not directly to the paddle 243.

The attachment mechanism 246 can be the same as the turnbuckle holder108 depicted in FIG. 7b , or it could be an alternative structure whichsimilarly allows movement, locking, and removal of the attachmentmechanism at a plurality of positions 247 along the support member 241.

The projection member 245 and its actuating mechanism can have astructure such as the turnbuckle rod 106 and threaded wheel 107 depictedin FIG. 7b . Alternatively, as depicted in FIG. 13, the projectionmember 245, locking mechanism 248, selectable actuating mechanism 249,and attachment mechanism 246 can have the structure of a ratchet rod gunassembly.

For added maneuverability, the attachment mechanism 246 can be connectedto the support member 241 by a detachable, lockable support bar joint250, such as a lockable ball joint, so that the attachment mechanism canbe rotated about the axes of the support member. This support bar jointcan be in addition to the detachable, lockable paddle joint 244 at thepaddle 243. Alternatively, the support bar joint 250 can be an optionalconfiguration that allows the paddle 243 to be rigidly connected to theprojection member 245.

The support member 241 includes lockable hinges 251, so that theportions of the support member lying distal to the stand 252 can moveoutwardly from the long axis of the stand to allow ingress and egress ofthe body part to be imaged.

The stand 252 is suitable to support a patient. The support member 241can be attached to the stand with a detachable, lockable stand connector253, such as a lockable ball joint, at a plurality of locations 254 toadjust to the size of the patient and the desired imaging area.Alternatively, the stand can be constructed of an inner and outercylinder to allow it to telescope upwardly or downwardly and lock intoposition with a spring-loaded button 255. To further support thepatient, a handle 256 can be included on the upper end of the stand.

The support member 241 can pivot on the stand connector 253, to allowthe support member and the paddles 243 attached to the support member tobe maneuvered into a desired position for imaging. Stand connector 253also allows different sized and shaped support members to be attachedand used with the stand.

FIG. 14 is a flow chart showing steps in a process of an embodiment ofthe invention for imaging. Depending on the body part involved and thepreferences of the operator, the process can be performed with the jigas shown in FIG. 7a and FIG. 7b , or with the jig shown in FIG. 13. Asshown in FIGS. 17 and 18, the process can also be performed with theoperator's hands 309 or, as shown in FIG. 19, by using a wrappingmaterial 310, preferably wrapping material at least partially includingmaterial with elastic properties.

In step 260, an operator selects paddle bars with surface areascoextensive with the target areas. In step 261, the operator selects apressing distance for each paddle in such a way that injury orsubstantial discomfort to the limb or other body tissues is avoided whenthe plurality of paddles are pressed against the target areas for ausable amount of time for an interface.

In step 262, the operator presses the plurality of paddles against thetarget areas by moving each of the paddles inwardly against the targetarea for the selected pressing distance for each paddle. Finally, instep 263, the operator locks each paddle into place at the selectedpressing distance for each paddle.

Although the invention has been described using specific terms, devices,and/or methods, such description is for illustrative purposes of thepreferred embodiment(s) only. Changes may be made to the preferredembodiment(s) by those of ordinary skill in the art without departingfrom the scope of the present invention, which is set forth in thefollowing claims. In addition, it should be understood that aspects ofthe preferred embodiment(s) generally may be interchanged in whole or inpart.

The invention claimed is:
 1. A method of manufacturing an interface fora body part having an underlying skeletal structure and an underlyingtissue lying within the body part, the method comprising: creating amodel of the body part; reducing a radial dimension of the model at afirst compression area, a second compression area, and a thirdcompression area; wherein the compression areas are disposedcircumferentially around a long axis of the model and approximatelyequally spaced; wherein each of the compression areas islongitudinal-shaped and has a longitudinal dimension that extendssubstantially along a long axis of the model; fabricating an interfacehaving a surface that mates with the compression-pattern of the modifiedmodel; and wherein the surface of the interface is sized and dimensionedto compress soft tissue of the body part against the skeletal structurewhen the interface is worn on the body part such that motion of theskeletal structure towards a wall of the interface is reduced.
 2. Themethod of claim 1, wherein the model is a physical model.
 3. The methodof claim 2, wherein the step of reducing a radial dimension of thephysical model is accomplished by subtracting material from an outersurface of the physical model.
 4. The method of claim 2, furthercomprising the step of increasing a radial dimension of the physicalmodel by adding material to an outer surface of the physical model. 5.The method of claim 2, further comprising the step of scanning a surfaceof the model.
 6. The method of claim 5, wherein the model is a positivemodel of the body part and the surface is an exterior wall of the model.7. The method of claim 5, wherein the model is a negative model of thebody part and the surface is an interior wall of the model.
 8. Themethod of claim 1, wherein the model is a virtual model.
 9. The methodof claim 8, wherein the step of reducing a radial dimension of thevirtual model is accomplished by extruding a surface of the virtualmodel inward towards a centerline of the limb.
 10. The method of claim9, further comprising the step of increasing a radial dimension of thevirtual model by extruding a surface of the virtual model outward awayfrom a centerline of the limb.
 11. The method of claim 1, wherein thestep of creating a model of the body part comprises imaging the bodypart to obtain a virtual model, and uploading the virtual model into acomputer-aided design (CAD) program.
 12. The method of claim 11, whereinthe body part is in an uncompressed state during scanning.
 13. Themethod of claim 12, wherein the body part is in a compressed stateduring scanning.
 14. The method of claim 1, wherein the step of creatinga model of the body comprises casting the body part.
 15. The method ofclaim 14, wherein the step of creating a model further comprises usingthe cast to make a positive model of the body part.
 16. The method ofclaim 14, wherein the step of creating a model further comprises imagingthe interior of the cast and uploading the virtual model into acomputer-aided design (CAD) program.
 17. The method of claim 14, whereinthe body part is in an uncompressed state during casting.
 18. The methodof claim 14, wherein the body part is in a compressed state duringcasting.